The present invention relates to a light-proof tearable wrapping or sheathing in which a pack of photographic or X-ray sheet films is enclosed and which wrapped pack is insertable in a film supply magazine of a sheet film cassette-loading device.
Light-proof removable wrappings or sheathings for film packs of sheet films have been known. Wrapped film packs are inserted in the supply magazine, at the side of which opposite to the side of the insertion of the film pack a pulling device is provided, which is preferably a winding device for the removal of the sheathing from the supply magazine. The sheathing of each film pack has a winding flap which, after the supply magazine with the film pack therein has been closed, is together with the sheathing removed from the magazine.
The film packs with such a sheathing are commercially available. The sheathing must be open in a dark room and the film pack be inserted into the film supply magazine. Efforts have been made to insert the film pack provided with a light-proof sheathing into the magazine at the day light and to open and remove the sheathing after closing of the magazine.
A supply magazine of the foregoing type has been disclosed in DE-GMS No. 77 25 804. A tearing flap of the sheathing is formed by labyrinth-shaped ends of the flap of the sheathing whereby a folding must be ripped due to a pulling force exerted by the rotation of a winding device provided on the supply magazine so that the sheathing is pulled from the film stack previously wrapped therein and wound on the winding device. It has been however established that the force applied to the winding device has not been sufficient to tear the flaps from each other. Thus the known device for operation at day light cannot be used for loading magazines and opening the sheathing of the pack in the closed magazine.
A supply magazine disclosed in DE-PS No. 34 05 423 is provided with a device for opening the pack sheathing, which device is usable with a specific type of film supply magazines. For other types of magazines for example such as disclosed in the aforementioned DE-GMS 77 25 804, a foled tearing flap of the sheathing must be pulled not by the winding device but by hand. The force, however, cannot be practically applied for tearing up of the folded flap.
A supply magazine disclosed in DE-OS No. 35 43 024 is utilized for pack sheathings which have a knife-shaped or saw blade-shaped tearing strip for removing the sheathing from the closed magazine. The disadvantage of this otherwise satisfactory device resides in that the day light loading of the supply magazine is possible only with a certain type of the magazine while film packs for loading of various types of the magazines, for example disclosed in DE-GMS No. 77 25 804 must be usable at day light.